Typical type error revising method when inputting characters (all types of inputtable characters including English characters, Korean characters, numbers, special characters, etc.) in personal computers or in mobile phones is to delete all words between the word including type error and the current cursor location using deletion function key like backspace, and retype the whole deleted words, or to move a cursor to the word including type error using a mouse (in case of personal computers) or using a finger touch (in case of mobile devices) and retype the word including type error.
However, when there exist correctly typed words between the word including type error and the current cursor location, the correctly typed words as well as the word including type error should be deleted when applying the typical type error revising method of inputting deletion function key like backspace. When moving a cursor using a mouse in personal computers, one of the hands should be relocated from a keyboard to a mouse, the cursor should be accurately placed in a location of type error through the mouse control, and the cursor should be returned to the previous location for resuming character input through the mouse control. This user attention requiring process is quite inconvenient. When moving a cursor using a finger touch in mobile devices, the accuracy of cursor control is not generally good enough to locate the cursor in a location of type error at one time and also requires user attention, thus is quite inconvenient.
The auto-correction function was developed in order to enhance user convenience in revising type errors. This auto-correction function has been already commercialized, and works to automatically correct the word “A,” which the user actually typed, to the word “B,” when the machine decides that the word “A” is a type error and should be revised to the word “B.” Automatically retyped word “B” should exist in a library of the machine, and is not required to be retyped by the user.
In the above auto-correction function, it is apparent that the retyped word “B” is not actually input by the user with the intention of revision, but is what the machine presumes that the user actually intended to input. Thus, there are problems when the accuracy of presumption is not good enough. The problematic accuracy of presumption is partly because of the limited number of words registered in a library of the machine. These days, many users frequently use newly coined words or new abbreviations, which are not covered by the old library, in typing environment of personal computers and mobile devices. Thus, if the library is not frequently updated, the limitation of the library becomes more and more remarkable. For this reason, many users turn the auto-correction function off when they input characters, even though their devices (personal computers or mobile devices) are equipped with the auto-correction function.
A further problem of the auto-correction function is that the auto-correction works only in a currently inputting word. Thus, when the users find that there are type errors in the already input words, not in the currently inputting words, like in the typical error revising methods described above, the words between the word including type errors and the current cursor location should be deleted through inputting the deletion function key like backspace, or a cursor should be moved by a mouse control or finger touch to the location of type errors.